The basic encodings

1. geoshape:color showing the severity of the pandemic, opacity showing clicked data, tooltip giving additional information and can be combined with the click feature.
2. barchart: vertically country is ranked by daily new cases descending while keeping the top 20 only

Interactions

1. time slider feature: the user can use a monthly slider to slide over the dataset that shows the aggregately new cases for each country.
2. interactive color changes: the color is a sequential color that shows a range between 0 to max(new cases), the sliding effect provides an intuitive sense of how the pandemic is evolving.
3. clickable feature: The user can click on a single country on the map or select the country from the top 20 bar chart; this will show the area with emphasis and at the same time make sure the user is clicking on the correct country when tooltip is providing additional information.